Image sensors

ABSTRACT

An image sensor includes a semiconductor substrate including a pixel region and a pad region, a plurality of photoelectric conversion regions in the pixel region, an interconnect structure on a front surface of the semiconductor substrate, a pad structure in the pad region and on a rear surface of the semiconductor substrate, a through via structure in the pad region and electrically connected to the interconnect structure through the semiconductor substrate, and an isolation structure at least partially extending through the pad region of the semiconductor substrate from the rear surface of the semiconductor substrate. The isolation structure surrounds the pad structure and the through via structure in a plane extending parallel to the rear surface of the semiconductor substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/108,348, filed on Aug. 22, 2018, which claims the benefit, under 35U.S.C. § 119, of Korean Patent Application No. 10-2017-0151720, filed onNov. 14, 2017, in the Korean Intellectual Property Office, thedisclosure of each of which is incorporated herein in its entirety byreference.

BACKGROUND

The inventive concepts relate to image sensors, and more particularly,to image sensors including a photodiode.

An image sensor is an apparatus configured to convert an optical imagesignal into an electrical signal. An image sensor may include a pixelregion including a plurality of photodiode regions which receiveincident light and which convert the light into an electrical signal,and a pad region that surrounds the pixel region. As integration of suchan image sensor increases, a size of each of the plurality of photodioderegions is reduced and, due to generation of a step difference betweenthe pixel and the pad region, manufacturing processes of the imagesensor become difficult or sensitivity of the image sensor deteriorates.

SUMMARY

The inventive concepts provide image sensors in which generation of astep difference between a pad region and a pixel region may be beingprevented, and in which sensitivity of the image sensor is preventedfrom deteriorating.

The inventive concepts provide compact image sensors.

According to an aspect of the inventive concepts, an image sensor mayinclude a semiconductor substrate including a pixel region and a padregion, a plurality of photoelectric conversion regions in the pixelregion, an interconnect structure on a front surface of thesemiconductor substrate, a pad structure in the pad region, the padstructure on a rear surface of the semiconductor substrate, a throughvia structure in the pad region, the through via structure electricallyconnected to the interconnect structure through the semiconductorsubstrate, and an isolation structure at least partially extendingthrough the pad region of the semiconductor substrate from the rearsurface of the semiconductor substrate. The isolation structure maysurround the pad structure and the through via structure in a planeextending parallel to the rear surface of the semiconductor substrate.

According to an aspect of the inventive concepts, an image sensor mayinclude a semiconductor substrate including a pixel region and a padregion, a plurality of photoelectric conversion regions in the pixelregion, an interconnect structure on a front surface of thesemiconductor substrate, a pad structure in the pad region, the padstructure embedded in the semiconductor substrate, the pad structureincluding an upper surface exposed to a rear surface of thesemiconductor substrate, and an isolation structure at least partiallyextending through the pad region of the semiconductor substrate from therear surface of the semiconductor substrate. The isolation structure maysurround the pad structure in a plane extending parallel to the rearsurface of the semiconductor substrate.

According to an aspect of the inventive concepts, an image sensor mayinclude a semiconductor substrate including a pixel region and a padregion, a plurality of photoelectric conversion regions in the pixelregion, an interconnect structure on a front surface of thesemiconductor substrate, a pad structure in the pad region, the padstructure on a rear surface of the semiconductor substrate, a throughvia structure in the pad region, the through via structure electricallyconnected to the interconnect structure through the semiconductorsubstrate, and an isolation structure at least partially extendingthrough the pad region of the semiconductor substrate from the rearsurface of the semiconductor substrate. The isolation structure maysurround the pad structure and the through via structure in a planeextending parallel to the rear surface of the semiconductor substrate. Aportion of the semiconductor substrate overlapping the pad structure maybe electrically insulated from another portion of the semiconductorsubstrate in the pixel region by the isolation structure.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments of the inventive concepts will be more clearlyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a layout diagram illustrating an image sensor according tosome example embodiments;

FIG. 2A is a cross-sectional view taken along line 1A-1A′ of FIG. 1;

FIG. 2B is an enlarged view of portion 1B of FIG. 1;

FIG. 3 is a cross-sectional view illustrating an image sensor accordingto some example embodiments;

FIG. 4 is a layout diagram illustrating an image sensor according tosome example embodiments;

FIG. 5 is a cross-sectional view taken along line 4A-4A′ of FIG. 4;

FIG. 6 is a cross-sectional view illustrating an image sensor accordingto some example embodiments;

FIG. 7 is a cross-sectional view illustrating an image sensor accordingto some example embodiments;

FIG. 8 is a cross-sectional view illustrating an image sensor accordingto some example embodiments;

FIG. 9 is a cross-sectional view illustrating an image sensor accordingto some example embodiments;

FIG. 10 is a cross-sectional view illustrating an image sensor accordingto some example embodiments;

FIG. 11 is a cross-sectional view illustrating an image sensor accordingto some example embodiments;

FIG. 12 is a cross-sectional view illustrating an image sensor accordingto some example embodiments;

FIGS. 13, 14, 15, 16, 17, 18, 19, 20, and 21 are cross-sectional viewsillustrating a method of manufacturing an image sensor according to someexample embodiments;

FIGS. 22 and 23 are cross-sectional views illustrating a method ofmanufacturing an image sensor according to some example embodiments;

FIG. 24 is a diagram illustrating an electronic device according to someexample embodiments;

FIG. 25 is a cross-sectional view showing a solar cell according to someexample embodiments;

FIG. 26 is a sectional view of an organic light-emitting displayapparatus according to some example embodiments;

FIG. 27 is a view showing a sensor according to some exampleembodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a layout diagram illustrating an image sensor according tosome example embodiments. FIG. 2A is a cross-sectional view taken alongline 1A-1A′ of FIG. 1. FIG. 2B is an enlarged view of portion 1B of FIG.1.

Referring to FIGS. 1 to 2B, an image sensor 100 may include a pixelregion APR including a plurality of photoelectric conversion regions 120and a pad region PDR arranged on at least one side of the pixel regionAPR. As shown in FIG. 1, for example, the pad region PDR may surroundthe pixel region APR.

The pixel region APR may be arranged on a semiconductor substrate 110 tohave an arbitrary shape. For example, as illustrated in FIG. 1, in thepixel region APR, the plurality of photoelectric conversion regions 120may be arranged in a matrix while forming columns and rows in a firstdirection (for example, an X direction of FIG. 1) that runs parallelwith an upper surface of the semiconductor substrate 110 and in a seconddirection (for example, a Y direction of FIG. 1) that runs parallel withthe upper surface of the semiconductor substrate 110 to be perpendicularto the first direction. The pad region PDR may be arranged on thesemiconductor substrate 110 to surround the pixel region APR.

The semiconductor substrate 110 may include a front surface 110F and arear surface 110B opposite to each other. Here, for convenience sake, asurface of the semiconductor substrate 110 on which a color filter 182is arranged is referred to as the rear surface 110B and a surfaceopposite to the rear surface 110B is referred to as the front surface110F. However, the inventive concepts are not limited thereto. Accordingto some example embodiments, the semiconductor substrate 110 may includea p-type semiconductor substrate. For example, the semiconductorsubstrate 110 may be formed of a p-type silicon substrate. According tosome example embodiments, the semiconductor substrate 110 may include ap-type bulk substrate and a p-type or n-type epitaxial layer grown onthe p-type bulk substrate. According to some example embodiments, thesemiconductor substrate 110 may include an n-type bulk substrate and ap-type or n-type epitaxial layer grown on the n-type bulk substrate. Thesemiconductor substrate 110 may be formed of an organic plasticsubstrate.

In the pixel region APR, the plurality of photoelectric conversionregions 120 may be arranged in the semiconductor substrate 110. Eachregion of the plurality of photoelectric conversion regions 120 mayinclude a photodiode region 122 and an impurity diffusion region (notshown).

Pixel isolation regions 124 partially pass (“extend”) through thesemiconductor substrate 110 and may be arranged between adjacent ones ofthe photoelectric conversion regions 120. The pixel isolation regions124 may be formed in pixel isolation trenches 124T that partially passthrough the semiconductor substrate 110. The plurality of photoelectricconversion regions 120 may be electrically insulated from neighboringphotoelectric conversion regions 120 by the pixel isolation regions 124.The pixel isolation regions 124 are arranged between adjacent ones ofthe plurality of photoelectric conversion regions 120 arranged in amatrix as illustrated in FIG. 1 and may be grid or mesh-shaped.According to some example embodiments, the pixel isolation regions 124may be formed of an insulation material such as a silicon oxide, asilicon nitride, or a silicon oxynitride.

A backside insulation layer 126 may be arranged on the rear surface 110Bof the semiconductor substrate 110. The backside insulation layer 126may be formed on the pixel region APR and the pad region PDR to auniform thickness. In addition, as illustrated in FIG. 2A, the backsideinsulation layer 126 is conformally formed on the pixel isolationtrenches 124T and the pixel isolation regions 124 may fill the pixelisolation trenches 124T on the backside insulation layer 126. Accordingto some example embodiments, the backside insulation layer 126 mayinclude an insulation material such as silicon oxide, silicon nitride,or silicon oxynitride. According to some example embodiments, thebackside insulation layer 126 may include a metal oxide such as hafniumoxide, aluminum oxide, or tantalum oxide. In this case, the backsideinsulation layer 126 may operate as a negative fixed charge layer.According to some example embodiments, the backside insulation layer 126is formed on internal walls of the pixel isolation trenches 124T and onthe rear surface 110B of the semiconductor substrate 110. Then, thepixel isolation regions 124 that fill residing portion of the pixelisolation trenches 124T may be formed. According to some exampleembodiments, the backside insulation layer 126 and the pixel isolationregions 124 may be formed of the same material in the same process. Insuch a case, an interface between the backside insulation layer 126 andthe pixel isolation region 124 may not be distinguished. As shown in atleast FIG. 2A, a side wall of the backside insulation layer 126 may beexposed through an internal wall of the pad trench 150T, and the padinsulation layer 156 may extend on the side wall of the backsideinsulation layer 126.

A first interconnect structure 130 may be arranged on the front surface110F of the semiconductor substrate 110. The first interconnectstructure 130 may include a first interconnect layer 131 and a secondinterconnect layer 132. Each of the first interconnect layer 131 and thesecond interconnect layer 132 may be formed of a lamination structure ofa plurality of layers. The first interconnect layer 131 and the secondinterconnect layer 132 may include at least one among polysilicon thatare doped with impurities or that are not doped with impurities, ametal, a metal silicide, a metal nitride, and a metal containing layer.For example, the first interconnect layer 131 and the secondinterconnect layer 132 may include tungsten (W), aluminum (Al), copper(Cu), tungsten silicide, titanium silicide, tungsten nitride, titaniumnitride, and doped polysilicon.

A first interlayer insulation layer 133 may be arranged to cover thefirst interconnect structure 130 on the front surface 110F of thesemiconductor substrate 110. The first interlayer insulation layer 133may include an insulation material such as silicon oxide, siliconnitride, or silicon oxynitride.

Although not shown, gate electrodes (not shown) that form a plurality oftransistors may be formed on the front surface 110F of the semiconductorsubstrate 110 and the first interconnect structure 130 may furtherinclude a via structure (not shown) that connects between the gateelectrodes and the first interconnect layer 131 or between the gateelectrode and the second interconnect layer 132. The gate electrodes andthe via structure may be covered with the first interlayer insulationlayer 133.

According to some example embodiments, the plurality of transistors mayinclude a transmission transistor (not shown) configured to transmitcharges generated by the photoelectric conversion regions 120 to afloating diffusion region, a reset transistor (not shown) configured toperiodically reset the charges stored in the floating diffusion region,a drive transistor (not shown) configured to function as a sourcefollower buffer amplifier and to buffer a signal in accordance with thecharges charged in the floating diffusion region, and a selectiontransistor (not shown) that performs switching and addressing in orderto select the pixel region APR. However, the plurality of transistorsare not limited thereto.

A through via structure 140 electrically connected to the firstinterconnect structure 130 may be arranged in the pad region PDR. A padstructure 150 electrically connected to the through via structure 140may be arranged at one side of the through via structure 140. As shownin at least FIG. 2A, in the pad region PDR, an isolation structure 160may be arranged to surround the through via structure 140 and the padstructure 150.

As illustrated in FIG. 2B, seen from the rear surface 110B of thesemiconductor substrate 110 (for example, seen in a Z direction), theisolation structure 160 is arranged to surround the through viastructure 140 and the pad structure 150 and the isolation structure 160may not be arranged between the through via structure 140 and the padstructure 150. Restated, as shown in at least FIGS. 2A-2B, an isolationstructure 160 may be arranged to surround the through via structure 140and the pad structure 150 in a plane extending parallel to the rearsurface 110B of the semiconductor substrate 110. A portion of thesemiconductor substrate 110 at least partially limited (“defined”) bythe isolation structure 160 is referred to as an isolation region IR.The isolation region IR may refer to a portion of the semiconductorsubstrate 110 that overlaps the through via structure 140 and the padstructure 150. As shown in at least FIG. 2A, the isolation region IR andthe pad structure 150 may overlap each other in a direction extendingperpendicular to the rear surface 110B of the semiconductor substrate110 (e.g., “may vertically overlap”). As shown in at least FIG. 2A, theisolation structure 160 may be not between the through via structure 140and the pad structure 150 within the semiconductor substrate 110.Restated, the pad structure 150 and the through via structure 140 may becollectively surrounded by the isolation structure 160 in the planeextending parallel to the rear surface 110B of the semiconductorsubstrate 110. The through via structure 140 may overlap the padstructure 150 in a direction extending perpendicular to the rear surface110B of the semiconductor substrate 110.

The isolation region IR is surrounded by the ring-shaped isolationstructure 160 and one pad structure 150 and three through via structures140 may be arranged in the isolation region IR. The inventive conceptionis not limited thereto. A plurality of pad structures 150 and aplurality of through via structures 140 may be arranged in the isolationregion IR.

The through via structure 140 may be arranged to fill the through viatrench 140T that passes through the semiconductor substrate 110. Thethrough via trench 140T may extend from the front surface 110F to therear surface 110B of the semiconductor substrate 110 over an entirethickness of the semiconductor substrate 110 (e.g., through thesemiconductor substrate 110). In FIG. 2A, a width of the through viatrench 140T at a level the same as that of the rear surface 110B of thesemiconductor substrate 110 is slightly larger than a width of thethrough via trench 140T at a level the same as that of the front surface110F. However, the inventive concepts are not limited thereto.

The through via structure 140 may include a first via conductive layer142 conformally formed on an internal wall of the through via trench140T and a second via conductive layer 144 formed on the first viaconductive layer 142 to fill the through via trench 140T. The first viaconductive layer 142 may extend from the internal wall of the throughvia trench 140T onto the backside insulation layer 126. The first viaconductive layer 142 may include a metal such as Ti, titanium nitride(TiN), tantalum (Ta), tantalum nitride (TaN), TiW, W, Al, cobalt (Co),nickel (Ni), or Cu. The second via conductive layer 144 may include ametal such as W, Al, Co, Ni, or Cu. For example, each of the first viaconductive layer 142 and the second via conductive layer 144 may beformed of (“may at least partially comprise”) a single metal layer or adouble layer of a plurality of metal materials. The second viaconductive layer 144 may include a material different from the first viaconductive layer 142. However, the inventive concepts are not limitedthereto. In addition, as illustrated in FIG. 2A, the second viaconductive layer 144 may completely fill the through via trench 140T.Unlike in FIG. 2A, the second via conductive layer 144 may fill only aportion (for example, an upper side wall of the through via trench 140T)of the through via trench 140T. As shown in FIG. 2A, the second viaconductive layer 144 may be isolated from direct contact with the padtrench 150T, and the first via conductive layer 142 may be connected tothe pad trench 150T and may be connected to at least one of the firstpad conductive layer 152 and the second pad conductive layer 154.

The through via structure 140 may be electrically connected to the firstinterconnect structure 130 through the semiconductor substrate 110. Forexample, as illustrated in FIG. 2A, the through via structure 140 may bearranged so that an end of the first via conductive layer 142 contactsthe second interconnect layer 132.

The pad structure 150 may be arranged on the rear surface 110B of thesemiconductor substrate 110 to be spaced apart, isolated from directcontact with, or separate from the through via structure 140 in adirection parallel with a front surface 110F of the semiconductorsubstrate 110. The pad structure 150 may be arranged in a pad trench150T formed on the rear surface 110B of the semiconductor substrate 110to have a first depth H1. The pad structure 150 may have a bottomsurface positioned at a lower level than (e.g., “proximate to the frontsurface 110F of the semiconductor substrate 110 in relation to”) therear surface 110B of the semiconductor substrate 110. The pad structure150 is buried or embedded in the semiconductor substrate 110. An uppersurface of the pad structure 150 may be exposed to the rear surface 110Bof the semiconductor substrate 110. The pad structure may be a burialtype pad in which at least a portion of the pad structure 150 is buriedin the semiconductor substrate 110.

The pad structure 150 may include a first pad conductive layer 152conformally formed on an internal wall of the pad trench 150T andcontacting and/or embedded in the semiconductor substrate 110 and asecond pad conductive layer 154 that fills a residual portion of the padtrench 150T on the first pad conductive layer 152. A pad insulationlayer 156 may be between the pad trench 150T and the first padconductive layer 152, such that the first pad conductive layer 152 is onthe pad insulation layer 156, and the second pad conductive layer 154 ison the pad insulation layer 156. Furthermore the pad insulation layer156 may be between the second pad conductive layer 154 and thesemiconductor substrate 110 and the pad insulation layer 156 may bebetween the first pad conductive layer 152 and the semiconductorsubstrate 110, and the second pad conductive layer 154 may be isolatedfrom direct contact with the semiconductor substrate 110 (e.g., by atleast the pad insulation layer 156) as a result.

The pad insulation layer 156 may be arranged on (e.g., may extendconformally on) an internal wall of the pad trench 150T in an entirearea of the rear surface 110B of the semiconductor substrate 110,wherein the pad trench 150T extends into the semiconductor substrate 110from the rear surface 110B of the semiconductor substrate 110. The padinsulation layer 156 may be arranged on the backside insulation layer126 in both of the pixel region APR and the pad region PDR. The padinsulation layer 156 may be formed of an insulation material such assilicon oxide, silicon nitride, or silicon oxynitride. The padinsulation layer 156 may have a first thickness of about several toabout several thousand Å in a third direction (a Z direction)perpendicular to an upper surface (e.g., rear surface 110B) of thesemiconductor substrate 110.

As the pad structure 150 is arranged in the isolation region IR, sincesufficient electric insulation may be secured between the pad structure150 and the pixel region APR, the first thickness of the pad insulationlayer 156 may be relatively small. The pad insulation layer 156 isformed on an entire upper surface of the pixel region APR and the padregion PDR and the pad insulation layer 156 arranged on the pixel regionAPR may operate as an anti-reflection layer. Therefore, if the firstthickness of the pad insulation layer 156 is large, sensitivity of theimage sensor may deteriorate. However, since the pad structure 150 isarranged in the isolation region IR, the first thickness of the padinsulation layer 156 may be relatively small so that sensitivity of thepixel region APR may not deteriorate.

The first pad conductive layer 152 may extend from the internal wall ofthe pad trench 150T to the rear surface 110B of the semiconductorsubstrate 110 and may be connected to the first via conductive layer142. The first pad conductive layer 152 may include a metal such as Ti,TiN, Ta, TaN, TiW, W, Al, Co, Ni, or Cu. For example, each of the firstpad conductive layer 152 and the second pad conductive layer 154 may beformed of a single metal layer or a double layer of a plurality of metalmaterials. The second pad conductive layer 154 may include a materialdifferent from the first pad conductive layer 152. However, theinventive concepts are not limited thereto.

The pad structure 150 may be electrically connected to the firstinterconnect structure 130 through the through via structure 140. Anexternal connection terminal (not shown) may be arranged on the padstructure 150. Through the external connection terminal, an imagesignal, a control signal, or a power voltage may be provided ortransmitted to the first interconnect structure 130.

The isolation structure 160 may include an isolation insulation layer162. The isolation insulation layer 162 may fill an isolation trench160T that at least partially passes (“extends”) through thesemiconductor substrate 110 in the pad region PDR, such that theisolation structure 160 at least partially extends through the padregion PDR from the rear surface 110B of the semiconductor substrate110. The isolation insulation layer 162 may include an insulationmaterial such as silicon oxide, silicon nitride, and silicon oxynitride.As illustrated in FIG. 2A, the backside insulation layer 126 isconformally formed on the isolation trench 160T and the isolationinsulation layer 162 may fill the isolation trench 160T on the backsideinsulation layer 126. However, the inventive concepts are not limitedthereto.

As illustrated in FIG. 2B, seen from the rear surface 110B of thesemiconductor substrate 110, the isolation structure 160 is separatefrom the through via structure 140 and the pad structure 150 by aparticular (or, alternatively, predetermined) distance and isring-shaped to surround the through via structure 140 and the padstructure 150. The isolation structure 160 has a square ring-shapedcross-section, a polygonal ring-shaped cross-section, a rounded squarering-shaped cross-section, an elliptical ring-shaped cross-section, orthe like. However, the inventive concepts are not limited thereto.

As illustrated in FIG. 2B, the isolation structure 160 is arranged atone side of the through via structure 140 and the pad structure 150 maybe arranged on the other side opposite to the one side of the throughvia structure 140. The isolation structure 160 may not be arranged in aregion between the through via structure 140 and the pad structure 150.In FIG. 2B, the pad structure 150 and the through via structure 140 donot overlap the isolation structure 160. However, unlike in FIG. 2B,portions of the first pad conductive layer 152 and the first viaconductive layer 142 may extend onto the rear surface 110B of thesemiconductor substrate 110 by a particular (or, alternatively,predetermined) length and may overlap the isolation structure 160. Insome example embodiments, and as shown in at least FIG. 2A, the firstvia conductive layer 142 and the first pad conductive layer 152 do notoverlap the isolation structure 160 in a direction extendingperpendicular to the rear surface 110B of the semiconductor substrate110.

As illustrated in FIG. 2B, the pad trench 150T may have a first width W1in a first direction (an X direction of FIG. 2B) that runs parallel withthe upper surface of the semiconductor substrate 110. The pad trench150T may be separate from the through via trench 140T by a firstdistance D1 in a first direction. Both side walls that face each otherin the first direction of the isolation structure 160 may be separatefrom each other by a second distance D2. That is, a width of theisolation region IR in the first direction may correspond to the seconddistance D2. In the isolation region IR, since the pad trench 150T andthe through via trench 140T may be separate from each other by the firstdistance D1, which is relatively small, an area of the pad region PDRmay be reduced.

In addition, as the pad insulation layer 156 is formed to a smallthickness, the second width W2 of the pad structure 150 arranged in thepad trench 150T in the first direction may be relatively large.

As illustrated in FIGS. 2A and 2B, as the isolation structure 160 may bearranged to at least partially pass through the semiconductor substrate110 and to surround the pad structure 150 and the through via structure140, the isolation region IR (e.g., the portion of the semiconductorsubstrate 110 overlapping the pad structure 150) may be electricallyinsulated from another portion of the semiconductor substrate 110 by theisolation structure 160. For example, the isolation region IR may beelectrically insulated from the semiconductor substrate 110 of the pixelregion APR and the isolation region IR may be electrically insulatedfrom another neighboring isolation region IR.

A passivation layer 180 may be arranged on a portion of an upper surfaceof the pad structure 150, the pad insulation layer 156, and the throughvia structure 140. The passivation layer 180 may cover the entire pixelregion APR. An entire upper surface of the pad region PDR excluding aportion of the upper surface of the pad structure 150 may be coveredwith the passivation layer 180. The passivation layer 180 may include aninsulation material such as silicon oxide, silicon nitride, and siliconoxynitride.

In the pixel region APR, a color filter 182 and a micro-lens 184 may bearranged on the passivation layer 180. On the front surface 110F of thesemiconductor substrate 110, a supporting substrate 186 may be arrangedwith the first interlayer insulation layer 133 interposed therebetween.

In general, when the pad structure is arranged on the rear surface 110Bof the semiconductor substrate 110, a step difference may be generatedbetween the upper surface of the pixel region APR and the upper surfaceof the pad region PDR due to a thickness of the pad structure. In aprocess of forming the color filter 182 on the pixel region APR, apatterning process defect may occur due to the step different. However,according to the above example embodiments, since the pad structure 150may have a burial type pad structure in which the pad structure 150 isarranged in the pad trench 150T, it may prevent a step difference frombeing generated between the upper surface of the pixel region APR andthe upper surface of the pad region PDR and to prevent a patterningdefect from occurring in a process of forming the color filter.

Additionally, in the burial type pad structure, in order to electricallyinsulate the pad structure 150 from the semiconductor substrate 110, thepad insulation layer 156 of a sufficient thickness may be formed. Inthis case, since the pad insulation layer 156 arranged on the pixelregion APR operates as a reflection preventing layer, sensitivity of theimage sensor may deteriorate. However, according to the above exampleembodiments, since the isolation structure 160 is arranged to surroundthe pad structure 150 and the through via structure 140, the padstructure 150 arranged in the isolation region IR may be sufficientlyelectrically insulated from the semiconductor substrate 110 outside theisolation region IR. Therefore, the pad insulation layer 156 may bethin, and thus, it may prevent sensitivity of the image sensor 100 fromdeteriorating, which occurs in a case that the thick pad insulationlayer 156 is arranged on the pixel region APR.

In addition, according to the above-described example embodiments, sincethe pad structure 150 and the through via structure 140 are separatefrom each other by a small distance in the isolation region IR, an areaof the pad region PDR may be reduced. Therefore, the image sensor may becompact.

In summary, the image sensor 100 according to the above-describedexample embodiments may have improved sensitivity and may be compact. Inaddition, it may prevent a patterning defect from being generated inmanufacturing processes of the image sensor 100.

FIG. 3 is a cross-sectional view illustrating an image sensor 100Aaccording to some example embodiments. FIG. 3 illustrates across-section taken along the line 1A-1A′. In FIG. 3, the same referencenumerals as those of FIGS. 1 and 2B denote the same elements. In FIG. 3,the pad insulation layer 156 described with reference to FIG. 2A may notbe formed.

Referring to FIG. 3, a pad structure 150A may include the first padconductive layer 152 formed on an internal wall of the pad trench 150Tand the second pad conductive layer 154 that fills the residual portionof the pad trench 150T on the first pad conductive layer 152.

As illustrated in FIG. 3, the first pad conductive layer 152 maydirectly contact the semiconductor substrate 110. In addition, as thepad insulation layer 156 is not formed, the first pad conductive layer152 may directly contact the backside insulation layer 126. The backsideinsulation layer 126 may include a side wall 126T exposed by the padtrench 150T and the first pad conductive layer 152 may extend onto theside wall 126T of the backside insulation layer 126.

In the pad region PDR, since the through via structure 140 and the padstructure 150A are surrounded by the isolation structure 160, theisolation region IR may be electrically insulated from the semiconductorsubstrate 110 other than the isolation region IR. Therefore, the padinsulation layer 156 for insulating the pad structure 150 from thesemiconductor substrate 110 may be omitted.

Since the pad insulation layer 156 is not formed on both the pixelregion APR and the pad region PDR, it may prevent sensitivity of theimage sensor 100A from deteriorating, which occurs in a case that thethick pad insulation layer 156 is arranged on the pixel region APR.

FIG. 4 is a layout diagram illustrating an image sensor 100B accordingto some example embodiments. FIG. 5 is a cross-sectional view takenalong line 4A-4A′ of FIG. 4. In FIGS. 4 and 5, the same referencenumerals as those of FIGS. 1 to 3 denote the same elements.

Referring to FIGS. 4 and 5, a through via structure 140B and a padstructure 150B may be arranged to overlap each other. Seen from the rearsurface 110B of the semiconductor substrate 110, the through viastructure 140B and the pad structure 150B are arranged to overlap andthe isolation structure 160 may surround entire side wall of the padstructure 150B.

A through via trench 140TB may extend from the front surface 110F of thesemiconductor substrate 110 toward the rear surface 110B to a particular(or, alternatively, predetermined) depth and may be connected to (orcommunicated with) a pad trench 150TB. The pad trench 150TB may extendfrom the rear surface 110B of the semiconductor substrate 110 toward thefront surface 110F and may be connected to an upper end of the throughvia trench 140TB.

The first via conductive layer 142 is conformally formed on an internalwall of the through via trench 140TB. The first via conductive layer 142and the first pad conductive layer 152 may be connected to each other ata connection point of the through via trench 140TB and the pad trench150TB.

According to some example embodiments, the first via conductive layer142 and the first pad conductive layer 152 may be formed of the samematerial in the same process. In such a case, as illustrated in FIG. 5,one conductive material may be continuously formed on internal walls ofthe through via trench 140TB and the pad trench 150TB. According to someexample embodiments, the first pad conductive layer 152 is formed afterthe first via conductive layer 142 is formed or the first via conductivelayer 142 may be formed after the first pad conductive layer 152 isformed.

The second via conductive layer 144 may be connected to the second padconductive layer 154 while filling the through via trench 140TB.According to some example embodiments, the second via conductive layer144 and the second pad conductive layer 154 may be formed of the samematerial in the same process.

According to the above-described example embodiments, as the padstructure 150B and the through via structure 140B are arranged tooverlap each other in the isolation region IR, an area of the pad regionPDR may be reduced and the image sensor 100B may be compact.

In addition, although the pad insulation layer 156 has a relativelysmall thickness, the pad structure 150B arranged in the isolation regionIR may be sufficiently electrically insulated from a portion of thesemiconductor substrate 110 outside the isolation region IR. Therefore,it may prevent sensitivity of the image sensor 100B from deteriorating,which occurs in a case that the thick pad insulation layer 156 isarranged on the pixel region APR.

FIG. 6 is a cross-sectional view illustrating an image sensor 100Caccording to some example embodiments. FIG. 6 illustrates across-section taken along the line 4A-4A′ of FIG. 4. In FIG. 6, the samereference numerals as those of FIGS. 1 to 5 denote the same elements.

Referring to FIG. 6, a through via structure 140C and a pad structure150C may be arranged to overlap each other. The pad insulation layer 156(refer to FIG. 5) may not be formed between the pad structure 150C andthe pad trench 150TB. The pad structure 150C may include the first padconductive layer 152 that directly contacts the internal wall of the padtrench 150TB and the second pad conductive layer 154 that fills aresidual portion of the pad trench 150TB on the first pad conductivelayer 152.

According to the above-described example embodiments, since the padstructure 150C and the through via structure 140C are arranged tooverlap in the isolation region IR, an area of the pad region PDR may bereduced and the image sensor 100C may be compact.

In addition, although the pad insulation layer 156 is not formed both ofthe pixel region APR and the pad region PDR, the pad structure 150Carranged in the isolation region IR may be sufficiently electricallyinsulated from a portion of the semiconductor substrate 110 outside theisolation region IR. Therefore, it may prevent sensitivity of the imagesensor 100C from deteriorating, which occurs in a case that the thickpad insulation layer 156 is arranged on the pixel region APR.

FIG. 7 is a cross-sectional view illustrating an image sensor 100Daccording to some example embodiments. FIG. 7 illustrates across-section taken along the line 4A-4A′ of FIG. 4. In FIG. 7, the samereference numerals as those of FIGS. 1 to 6 denote the same elements. InFIG. 7, the pad trench 150TB described with reference to FIG. 5 may notbe formed.

Referring to FIG. 7, a through via trench 140TD may extend to passthrough the semiconductor substrate 110 and a pad structure 150D may beon a through via structure 140D. For example, the pad structure 150D mayinclude the first pad conductive layer 152 and the second pad conductivelayer 154 that are sequentially formed on the backside insulation layer126, and the backside insulation layer 126 may be connected to theisolation structure 160. Additionally, the pad structure 150D may be onthe backside insulation layer 126. The through via structure 140D andthe pad structure 150D may be arranged to overlap. As shown in FIG. 7,the pad structure 150D may have a bottom surface positioned at a higherlevel than (e.g., “distal from the semiconductor substrate 110 inrelation to”) the rear surface 110B of the semiconductor substrate 110.

According to the above-described example embodiments, since the padstructure 150D and the through via structure 140D are arranged tooverlap in the isolation region IR, an area of the pad region PDR may bereduced and the image sensor 100D may be compact.

In addition, although the pad insulation layer is not formed on both thepixel region APR and the pad region PDR, the pad structure 150D arrangedin the isolation region IR may be sufficiently electrically insulatedfrom a portion of the semiconductor substrate 110 outside the isolationregion IR. Therefore, it may prevent sensitivity of the image sensor100D from deteriorating, which occurs in a case that the thick padinsulation layer 156 is arranged on the pixel region APR.

FIG. 8 is a cross-sectional view illustrating an image sensor 100Eaccording to some example embodiments. FIG. 8 illustrates across-section taken along the line 1A-1A′ of FIG. 1. In FIG. 8, the samereference numerals as those of FIGS. 1 to 7 denote the same elements.

Referring to FIG. 8, a pixel isolation region 124A may include a pixelisolation insulation layer 124Aa and an impurity region 124Ab. The pixelisolation trench 124T may extend from the rear surface 110B of thesemiconductor substrate 110 toward the front surface 110F so as topartially pass through the semiconductor substrate 110. The pixelisolation insulation layer 124Aa may fill the pixel isolation trench124T. The impurity region 124Ab may be formed under the pixel isolationinsulation layer 124Aa.

An isolation structure 160A may include an isolation insulation layer162Aa and an impurity region 162Ab. An isolation trench 160T may extendfrom the rear surface 110B of the semiconductor substrate 110 toward thefront surface 110F so as to partially pass through the semiconductorsubstrate 110. The isolation insulation layer 162Aa may fill theisolation trench 160T. The impurity region 162Ab may be formed under theisolation insulation layer 162Aa.

FIG. 9 is a cross-sectional view illustrating an image sensor 100Faccording to some example embodiments. FIG. 9 illustrates across-section taken along the line 1A-1A′ of FIG. 1. In FIG. 9, the samereference numerals as those of FIGS. 1 to 8 denote the same elements.

Referring to FIG. 9, a pixel isolation region 124B may include a pixelisolation insulation layer 124Ba and a pixel isolation conductive layer124Bb. The pixel isolation trench 124T may extend from the front surface110F of the semiconductor substrate 110 toward the rear surface 110B soas to pass through the semiconductor substrate 110. The pixel isolationinsulation layer 124Ba is conformally formed on a side wall of the pixelisolation trench 124T and the pixel isolation conductive layer 124Bb mayfill the pixel isolation trench 124T on the pixel isolation insulationlayer 124Ba.

In FIG. 9, the pixel isolation trench 124T extends from the frontsurface 110F of the semiconductor substrate 110 toward the rear surface110B so as to pass through the semiconductor substrate 110. The pixelisolation trench 124T is illustrated as having the largest width at thesame level as the front surface 110F of the semiconductor substrate 110.However, according to some example embodiments, the pixel isolationtrench 124T extends from the rear surface 110B of the semiconductorsubstrate 110 toward the front surface 110F so as to pass through thesemiconductor substrate 110 and the pixel isolation trench 124T may havethe largest width at the same level as the rear surface 110B of thesemiconductor substrate 110.

Although not shown, an additional interconnect structure (not shown)electrically connected to the pixel isolation conductive layer 124Bb maybe formed. A negative voltage may be applied to the pixel isolationconductive layer 124Bb through the additional interconnect structure.Therefore, since it may prevent holes from being accumulated on asurface of the pixel isolation insulation layer 124Ba, it may reducegeneration of a dark current of the image sensor 100F.

FIG. 10 is a cross-sectional view illustrating an image sensor 100Gaccording to some example embodiments. FIG. 10 illustrates across-section taken along the line 1A-1A′ of FIG. 1. In FIG. 10, thesame reference numerals as those of FIGS. 1 to 9 denote the sameelements.

Referring to FIG. 10, a pad structure 150G may include a first padconductive layer 152G conformally formed on an internal wall of the padtrench 150T and a second pad conductive layer 154G formed on the firstpad conductive layer 152G not to completely fill the pad trench 150T. Agap 154GS may be formed between a side wall 154GW of the second padconductive layer 154G and the first pad conductive layer 152G arrangedon a side wall of the pad trench 150T. According to some exampleembodiments, the second pad conductive layer 154G may be formed byforming the first pad conductive layer 152G on an internal wall of thepad trench 150T, forming a conductive layer (not shown) on the first padconductive layer 152G to fill the pad trench 150T, and patterning theconductive layer.

FIG. 11 is a cross-sectional view illustrating an image sensor 100Haccording to some example embodiments. FIG. 11 illustrates across-section taken along the line 1A-1A′ of FIG. 1. In FIG. 11, thesame reference numerals as those of FIGS. 1 to 10 denote the sameelements.

Referring to FIG. 11, the image sensor 100H may have a stackingstructure in which the semiconductor substrate 110 and a lower substrate170 are attached to each other.

In the lower substrate 170, an active region (not shown) limited byisolation layers 1701 may be formed. Gate structures 172G may bearranged on the lower substrate 170. The gate structures 172G mayconfigure a plurality of complementary metal-oxide-semiconductor (CMOS)transistors for providing a uniform signal to the respectivephotoelectric conversion regions 120 or for controlling output signalsfrom the respective photoelectric conversion regions. For example, thetransistor may configure each of various kinds of logic circuits such asa timing generator, a row decoder, a row driver, a correlated doublesampler (CDS), an analog to digital converter (ADC), a latch, and acolumn decoder. However, the inventive concepts are not limited thereto.

A second interconnect structure 174 may be formed above the lowersubstrate 170. The second interconnect structure 174 may include a thirdinterconnect layer 175 and a fourth interconnect layer 176. A secondinterlayer insulation layer 178 may be arranged on the lower substrate170 to cover the gate structures 172G and the second interconnectstructure 174.

The first interlayer insulation layer 133 may be attached on the secondinterlayer insulation layer 178. According to some example embodiments,the first interlayer insulation layer 133 and the second interlayerinsulation layer 178 may be attached to each other by an oxide-oxidedirect bonding method. According to some example embodiments, anadhesive member (not shown) may be interposed between the firstinterlayer insulation layer 133 and the second interlayer insulationlayer 178.

The through via trench 140T passes through the semiconductor substrate110 and the first interlayer insulation layer 133 and may be connectedto a portion of the second interconnect structure 174. As illustrated inFIG. 11, the through via structure 140 is connected to both the firstinterconnect structure 130 and the second interconnect structure 174 anda bottom of the through via structure 140 may be surrounded by thesecond interlayer insulation layer 178.

FIG. 12 is a cross-sectional view illustrating an image sensor 100Iaccording to some example embodiments. FIG. 12 illustrates across-section taken along the line 1A-1A′ of FIG. 1. In FIG. 12, thesame reference numerals as those of FIGS. 1 to 11 denote the sameelements.

Referring to FIG. 12, the image sensor 100I has a stacking structure inwhich the semiconductor substrate 110 and the lower substrate 170 areattached to each other. The pad insulation layer 156 described withreference to FIG. 11 may not be formed.

FIGS. 13 to 21 are cross-sectional views illustrating a method ofmanufacturing the image sensor 100H according to some exampleembodiments. In FIGS. 13 to 21, cross-sections corresponding to thecross-section taken along the line 1A-1A′ are illustrated in a processorder. In FIGS. 13 to 21, the same reference numerals as those of FIGS.1 to 12 denote the same reference numerals.

Referring to FIG. 13, after forming the isolation layers 1701 thatdefine the active region (not shown) on the lower substrate 170, thegate structures 172G may be formed on the lower substrate 170. Then, thesecond interconnect structure 174 and the second interlayer insulationlayer 178 that covers the second interconnect structure 174 may beformed by forming a conductive layer (not shown) on the lower substrate170, patterning the conductive layer, and forming an insulation layer(not shown) to cover the patterned conductive layer.

Then, the semiconductor substrate 110 that includes the front surface110F and the rear surface 110B that are opposite to each other isprovided.

The photoelectric conversion regions 120 and a well region (not shown)may be formed by implanting ions from the front surface 110F of thesemiconductor substrate 110. For example, the photoelectric conversionregions 120 may be formed by doping n-type impurities and the wellregion may be formed by doping p-type impurities.

Then, the first interconnect structure 130 and the first interlayerinsulation layer 133 that covers the first interconnect structure 130may be formed on the semiconductor substrate 110 by forming a conductivelayer (not shown) on the front surface 110F of the semiconductorsubstrate 110, patterning the conductive layer, and forming aninsulation layer (not shown) to cover the patterned conductive layer.

Then, the lower substrate 170 may be attached to the semiconductorsubstrate 110. For example, the lower substrate 170 may be attached tothe semiconductor substrate 110 so that the first interlayer insulationlayer 133 directly contacts the second interlayer insulation layer 178by an oxide-oxide direct bonding method.

Referring to FIG. 14, the pixel isolation trench 124T and the isolationtrench 160T may be formed by forming a first mask pattern (not shown) onthe rear surface 110B of the semiconductor substrate 110 and etching thesemiconductor substrate 110 from the rear surface 110B by using the maskpattern as an etching mask.

According to some example embodiments, the pixel isolation trench 124Tand the isolation trench 160T may be formed not to completely passthrough the semiconductor substrate 110 such that the semiconductorsubstrate 110 is exposed at a bottom of the pixel isolation trench 124Tand a bottom of the isolation trench 160T.

According to some example embodiments, the pixel isolation trench 124Tand the isolation trench 160T may be formed to completely pass throughthe semiconductor substrate 110. The first interlayer insulation layer133 may be exposed by the bottom of the pixel isolation trench 124T andthe bottom of the isolation trench 160T.

According to some example embodiments, the pixel isolation region 124Aand the isolation structure 160A that are illustrated in FIG. 8 may beformed by forming the pixel isolation trench 124T and the isolationtrench 160T not to completely pass through the semiconductor substrate110 and performing an ion implantation process on the semiconductorsubstrate 110 exposed by the bottom of the pixel isolation trench 124Tand the bottom of the isolation trench 160T.

According to some example embodiments, after forming the pixel isolationtrench 124T, the isolation trench 160T may be formed.

Referring to FIG. 15, the backside insulation layer 126 may be formed onthe rear surface 110B of the semiconductor substrate 110 and on internalwalls of the pixel isolation trench 124T and the isolation trench 160Tby using an insulation material by a chemical vapor deposition (CVD)process and an atomic layer deposition (ALD) process.

The pixel isolation regions 124 and the isolation insulation layer 162may be formed in the pixel isolation trench 124T and the isolationtrench 160T by forming an insulation layer (not shown) that fills thepixel isolation trench 124T and the isolation trench 160T on the rearsurface 110B of the semiconductor substrate 110 and planarizing an upperportion of the insulation layer until an upper surface of the backsideinsulation layer 126 is exposed. Here, the isolation region IR may bedefined in a portion of the semiconductor substrate 110 surrounded bythe isolation insulation layer 162.

Referring to FIG. 16, the pad trench 150T may be formed by forming asecond mask pattern (not shown) on the backside insulation layer 126 andetching the backside insulation layer 126 and the semiconductorsubstrate 110 by using the second mask pattern as an etching mask. Theside wall 126T of the backside insulation layer 126 may be exposed bythe pad trench 150T.

Referring to FIG. 17, the pad insulation layer 156 may be formed oninternal walls of the backside insulation layer 126 and the pad trench150T. For example, the pad insulation layer 156 may be formed of aninsulation material by the CVD process and the ALD process.

As the pad trench 150T forms the isolation region IR, the pad insulationlayer 156 may have a relatively small thickness. The pad insulationlayer 156 may have a first thickness of about several A to about severalhundred nm. In general, since the pad insulation layer 156 includes aninsulation material, the pad insulation layer 156 may operates as areflection preventing layer. As the thickness of the pad insulationlayer 156 is larger, since an amount light incident on a pixel region isreduced, sensitivity of the image sensor may deteriorate. However,according to the embodiments, since the pad insulation layer 156 isformed in the isolation region IR, the pad insulation layer may have arelatively small thickness. Therefore, it may prevent sensitivity of theimage sensor from deteriorating.

Unlike in FIG. 17, the pad insulation layer 156 may not be formed. Inthis case, the image sensor 100A described with reference to FIG. 3 maybe formed. As described above, the pad trench 150T may be formed in theisolation region IR and the pad structure 150 (refer to FIG. 2A)arranged in the pad trench 150T may be electrically insulated from aregion outside the isolation region IR. Therefore, the pad insulationlayer 156 may be omitted so that it may prevent sensitivity of the imagesensor from deteriorating.

Referring to FIG. 18, the through via trench 140T may be formed byforming a third mask pattern (not shown) on the pad insulation layer 156and by sequentially etching the pad insulation layer 156, the backsideinsulation layer 126, the semiconductor substrate 110, the firstinterlayer insulation layer 133, and the second interlayer insulationlayer 178 by using the third mask pattern as an etching mask.

The through via trench 140T may be arranged in the isolation region IRto be separate from the pad trench 150T by a first distance. The throughvia trench 140T is separate from the pad trench 150T by a first distanceD1, which is relatively small. Therefore, a width D2 of the isolationregion IR may be small. That is, since the isolation structure 160 isnot between the through via trench 140T and the pad trench 150T, thedistance D1 from the through via trench 140T to the pad trench 150Tand/or the width D2 of the isolation region IR may be small. Therefore,the pad region PDR may be small.

Referring to FIG. 19, a first conductive layer 152P may be conformallyformed on the pad insulation layer 156 and on internal walls of thethrough via trench 140T and the pad trench 150T. The first conductivelayer 152P may be formed of a metal such as Ti, TiN, Ta, TaN, TiW, W,Al, Co, Ni, or Cu by the CVD process and the ALD process. The firstconductive layer 152P may be electrically connected to the secondinterconnect structure 174 on the bottom of the through via trench 140T.

Referring to FIG. 20, a second conductive layer 154P may be formed onthe first conductive layer 152P to a thickness sufficient to fill aresidual portion of the through via trench 140T and the residual portionof the pad trench 150T. The second conductive layer 154P may be formedof a metal such as W, Al, Co, Ni, or Cu by using the CVD process, theALD process, or a plating process.

According to some example embodiments, the second conductive layer 154Pmay completely fill the through via trench 140T. According to someexample embodiments, the second conductive layer 154P may fill only anupper entrance of the through via trench 140T.

Referring to FIG. 21, the second pad conductive layer may be left in thepad trench 150T and the second via conductive layer 144 may be left inthe through via trench 140T by removing an upper portion of the secondconductive layer 154P by a planarization process until an upper surfaceof the first conductive layer 152P (refer to FIG. 20) is exposed.

The first via conductive layer 142 and the first pad conductive layer152 may be left by forming a fourth mask pattern (not shown) on theexposed upper surface of the first conductive layer 152P and patterningthe first conductive layer 152P by using the fourth mask pattern as anetching mask. The first via conductive layer 142 may extend onto theupper surface of the pad insulation layer 156 while surrounding a sidewall and bottom surface of the second via conductive layer 144. Thefirst pad conductive layer 152 may extend onto the pad insulation layer156 while surround a side wall and a bottom surface of the second padconductive layer 154. The first pad conductive layer is connected to thefirst via conductive layer 142 on the pad insulation layer 156 so thatthe through via structure 140 and the pad structure 150 electricallyconnected to the through via structure 140 may be formed.

The pad structure 150 may have a second width W2 in a first direction(an X direction) and the pad insulation layer 156 is formed to a smallthickness so that the second width W2 of the pad structure 150 may belarge.

Referring to FIG. 11 again, the upper surface of the pad structure 150may be exposed by forming the passivation layer 180 on the rear surface110B of the semiconductor substrate 110 and patterning the passivationlayer 180.

Then, the color filter 182 and the micro-lens 184 may be formed on thepassivation layer.

The pad structure 150 has the upper surface at the same level as theupper surface of the through via structure 140 and a difference in levelbetween the upper surface of the pixel region APR and the upper layer ofthe pad region PDR may be negligible. Therefore, it may prevent apatterning defect from being generated in a coating layer patterningprocess for forming the color filter 182 and the micro-lens 184.

The image sensor 100H may be completed by the above process.

FIGS. 22 and 23 are cross-sectional views illustrating a method ofmanufacturing the image sensor 100I according to some exampleembodiments. In FIGS. 22 to 23, cross-sections corresponding to thecross-section taken along the line 1A-1A′ are illustrated in a processorder. In FIGS. 22 to 23, the same reference numerals as those of FIGS.1 to 21 denote the same reference numerals.

The pixel isolation region 124A and the isolation structure 160A may beformed in the semiconductor substrate 110 by performing the processesdescribed with reference to FIGS. 13 to 15.

Referring to FIG. 22, the through via trench 140T and the pad trench150T may be formed by forming the second mask pattern (not shown) on thebackside insulation layer 126 and etching the backside insulation layer126 and the semiconductor substrate 110 by using the second mask patternas an etching mask. In a process of forming the through via trench 140Tand the pad trench 150T, a side wall 126T of the backside insulationlayer 126 may be exposed by the pad trench 150T.

According to some example embodiments, the through via trench 140T andthe pad trench 150T may be formed in the same process. However, theinventive concepts are not limited thereto. According to some exampleembodiments, after forming the through via trench 140T, the pad trench150T may be formed.

Referring to FIG. 23, the first conductive layer 152P may be conformallyformed on the backside insulation layer 126 and on the internal walls ofthe through via trench 140T and the pad trench 150T. The firstconductive layer 152P may be electrically connected to the secondinterconnect structure 174 on the bottom of the through via trench 140T.

Referring to FIG. 23, the second pad conductive layer 154 may be left inthe pad trench 150T and the second via conductive layer 144 may be leftin the through via trench 140T by forming the second conductive layer154P (refer to FIG. 20) on the first conductive layer 152P (refer toFIG. 22) to have a thickness sufficient to fill the residual portion ofthe through via trench 140T and the residual portion of the pad trench150P, and removing an upper portion of the second conductive layer 154Pby a planarization process until an upper surface of the firstconductive layer 152P is exposed.

The pad structure 150A may be formed to have a second width W2A in thefirst direction (the X direction). Unlike in FIG. 20, since the padinsulation layer 156 is not formed, the second width W2A of the padstructure 150A may be relatively large.

Then, the image sensor 100I may be completed by performing the processdescribed with reference to FIG. 21.

According to the method of manufacturing the image sensor 100I, sincethe pad trench 150T and the through via trench 140T may besimultaneously formed, the image sensor 100I may be formed by simplifiedprocesses.

An image sensor as described herein may be included in an electronicdevice. As described herein, the electronic device may be for exampleany electronic device having a structure including an electrode, anactive layer, and an encapsulation film. For example, the electronicdevice may be a photoelectric device, an organic light emitting diode, asolar cell, a photosensor, and the like, but is not limited thereto.

The electronic device may be various electronic apparatuses, for examplea mobile phone, a digital camera, a solar cell, an organic lightemitting diode (OLED) display, and the like, but is not limited thereto.

FIG. 24 is a diagram illustrating an electronic device 2400 according tosome example embodiments.

Referring to FIG. 24, the electronic device 2400 includes a memory 2420,a processor 2430, a device 2440, and a communication interface 2450. Thedevice 2440 may include any of the electronic devices illustrated anddescribed herein.

The electronic device 2400 may be included in one or more variouselectronic devices, including, for example, a mobile phone, a digitalcamera, a sensor device, a biosensor device, and the like. In someexample embodiments, the electronic device 2400 may include one or moreof an image providing server, a mobile device, a computing device, animage outputting device, and an image capturing device. A mobile devicemay include a mobile phone, a smartphone, a personal digital assistant(PDA), some combination thereof, or the like. A computing device mayinclude a personal computer (PC), a tablet computer, a laptop computer,a netbook, some combination thereof, or the like. An image outputtingdevice may include a TV, a smart TV, some combination thereof, or thelike. An image capturing device may include a camera, a camcorder, somecombination thereof, or the like.

The memory 2420, the processor 2430, the device 2440, and thecommunication interface 2450 may communicate with one another through abus 2410.

The communication interface 2450 may communicate data from an externaldevice using various Internet protocols. The external device mayinclude, for example, an image providing server, a display device, amobile device such as, a mobile phone, a smartphone, a personal digitalassistant (PDA), a tablet computer, and a laptop computer, a computingdevice such as a personal computer (PC), a tablet PC, and a netbook, animage outputting device such as a TV and a smart TV, and an imagecapturing device such as a camera and a camcorder.

The processor 2430 may execute a program and control the electronicdevice 2400. A program code to be executed by the processor 2430 may bestored in the memory 2420. An electronic system may be connected to anexternal device through an input/output device (not shown) and exchangedata with the external device.

The memory 2420 may store information. The memory 2420 may be a volatileor a nonvolatile memory. The memory 2420 may be a non-transitorycomputer readable storage medium. The memory may store computer-readableinstructions that, when executed, cause the execution of one or moremethods, functions, processes, etc. as described herein. In some exampleembodiments, the processor 2430 may execute one or more of thecomputer-readable instructions stored at the memory 2420.

In some example embodiments, the communication interface 2450 mayinclude a USB and/or HDMI interface. In some example embodiments, thecommunication interface 2450 may include a wireless communicationinterface.

FIG. 25 is a cross-sectional view showing a solar cell 2500 according tosome example embodiments. Referring to FIG. 25, a solar cell 2500includes a first electrode 2502 and a second electrode 2510, and aphotoactive layer 2506 positioned between the first electrode 2502 andthe second electrode 2510.

A substrate (not shown) may be positioned at the first electrode 2502 orthe second electrode 2510, and may include a light-transmittingmaterial. The light-transmitting material may include, for example, aninorganic material (e.g., glass), or an organic material (e.g.,polycarbonate, polymethylmethacrylate, polyethylene terephthalate,polyethylene naphthalate, polyamide, polyethersulfone, or a combinationthereof).

One of the first electrode 2502 and the second electrode 2510 is ananode and the other is a cathode. At least one of the first electrode2502 and second electrode 2510 may be a light-transmitting electrode,and light may enter toward the light-transmitting electrode. Thelight-transmitting electrode may be made of, for example, a conductiveoxide (e.g., indium tin oxide (ITO)), indium doped zinc oxide (IZO), tinoxide (SnO2), aluminum-doped zinc oxide (AZO), and/or gallium-doped zincoxide (GZO), or a transparent conductor of a conductive carbon composite(e.g., carbon nanotubes (CNT) or graphenes). At least one of the firstelectrode 2502 and the second electrode 2510 may be an opaque electrode,which may be made of an opaque conductor, for example, aluminum (Al),silver (Ag), gold (Au), and/or lithium (Li).

The photoactive layer 2506 may include an electronic device according tosome example embodiments as described herein.

First and second auxiliary layers 2504 and 2508 may be positionedbetween the first electrode 2502 and the photoactive layer 2506 andbetween the second electrode 2510 and the photoactive layer 2506,respectively. The first and second auxiliary layers 2504 and 2508 mayincrease charge mobility between the first electrode 2502 and thephotoactive layer 2506 and between the second electrode 2510 and thephotoactive layer 2506. The first and second auxiliary layers 2504 and2506 may be at least one selected from, for example, an electroninjection layer (EIL), an electron transport layer, a hole injectionlayer (HIL), a hole transport layer, and a hole blocking layer, but arenot limited thereto. One or both of the first and second auxiliarylayers 2504 and 2508 may be omitted.

The photoactive layer 2506 may have a tandem structure where at leasttwo thereof are stacked.

FIG. 26 is a sectional view of an organic light-emitting displayapparatus 2600 according to some example embodiments.

Referring to FIG. 26, a first electrode 2603 a and a second electrode2603 b are positioned on a substrate 2601, a first emission layer 2605 ais positioned on the first electrode 2603 a, and a second emission layer2605 b is positioned under the second electrode 2603 b.

The substrate 2601 may include a material selected from the groupconsisting of glass, quartz, silicon, a synthetic resin, a metal, and acombination thereof. The synthetic resin may include polyethylenenaphthalate (PEN), polyethylene terephthalate (PET), polycarbonate,polyvinyl alcohol, polyacrylate, polyimide, polynorbornene and/orpolyethersulfone (PES), etc. The metal plate may include a stainlesssteel foil and/or an aluminum foil, etc.

The first electrode 2603 a may include a material having a work functionof about 4.3 eV to about 5.0 eV, about 4.3 eV to about 4.7 eV, or about4.3 eV to about 4.5 eV. According to example embodiments, the materialmay include aluminum (Al), copper (Cu), magnesium (Mg), molybdenum (Mo)and/or an alloy thereof, etc. In addition, these metals may be laminatedto provide a first electrode. The first electrode 2603 a may have athickness of about 260 to about 260 nm.

The second electrode 2603 b may include a material having a workfunction of about 26.3 eV to about 26.7 eV or about 26.5 eV to about26.7 eV. According to some example embodiments, the second electrode2603 b may include Ba:Al. The second electrode 2603 b may have athickness of about 260 to about 260 nm.

The first emission layer 2605 a and the second emission layer 2605 b mayinclude an electronic device according to some example embodiments asdescribed herein.

A middle electrode 2609 is positioned between the first emission layer2605 a and the second emission layer 2605 b. The middle electrode 2609may include a material having a work function of about 5.0 eV to about5.2 eV. According to some example embodiments, the material may includea conductive polymer. The conductive polymer may include polythiophene,polyaniline, polypyrrole, polyacene, polyphenylene,polyphenylenevinylene, a derivative thereof, a copolymer thereof, or amixture thereof.

A buffer layer 2607 may be positioned between the first emission layer2605 a and the middle electrode 2609, and may include a materialselected from the group consisting of a metal oxide, a polyelectrolyte,and combinations thereof. The combination thereof refers to the metaloxide and polyelectrolyte being mixed or laminated to provide amulti-layer. In addition, the different kinds of metal oxide orpolyelectrolyte may be laminated.

FIG. 27 is a view showing a sensor 2700 according to some exampleembodiments.

Referring to FIG. 27, a sensor 2700 (for example a gas sensor, lightsensor, energy sensor, but example embodiments are not limited thereto)includes at least one electrode 2720 configured to output a signal to aprocessor 2730. The processor 2730 may include a microprocessor, butexample embodiments are not limited thereto. The electrode 2720 mayinclude an electronic device according to some example embodiments asdescribed herein.

While the inventive concepts has been particularly shown and describedwith reference to embodiments thereof, it will be understood thatvarious changes in form and details may be made therein withoutdeparting from the spirit and scope of the following claims.

What is claimed is:
 1. An image sensor comprising: a semiconductorsubstrate including a pixel region and a pad region; a plurality ofphotoelectric conversion regions in the pixel region; an interconnectstructure on a front surface of the semiconductor substrate; a padstructure in the pad region, the pad structure on a rear surface of thesemiconductor substrate; at least two through via structures in the padregion, each of the at least two through via structures electricallyconnected to the interconnect structure through the semiconductorsubstrate; and an isolation structure at least partially extending intothe semiconductor substrate and through the pad region of thesemiconductor substrate from the rear surface of the semiconductorsubstrate, in a direction extending perpendicular to the rear surface ofthe semiconductor substrate, the isolation structure surrounding all ofthe pad structure and all of the at least two through via structures ina plane extending parallel to the rear surface of the semiconductorsubstrate.
 2. The image sensor of claim 1, wherein the isolationstructure at least partially defines an isolation region in thesemiconductor substrate, and the isolation region and the pad structureoverlap each other in the direction extending perpendicular to the rearsurface of the semiconductor substrate.
 3. The image sensor of claim 1,wherein the isolation structure is not between the pad structure and theat least two through via structures within the semiconductor substrate,and the isolation structure is not between two adjacent through viastructures of the at least two through via structures within thesemiconductor substrate.
 4. The image sensor of claim 1, wherein the padstructure comprises: a pad insulation layer extending conformally on aninternal wall of a pad trench extending into the semiconductor substratefrom the rear surface of the semiconductor substrate; and a padconductive layer on the pad insulation layer, the pad conductive layerfilling the pad trench.
 5. The image sensor of claim 4, wherein the atleast two through via structures are spaced apart from the pad structurein a direction parallel with the rear surface of the semiconductorsubstrate, each of the at least two through via structures includes avia conductive layer on an internal wall of a through via trench, thethrough via trench extending through the semiconductor substrate, thevia conductive layer isolated from direct contact with the pad trench,and a portion of the pad conductive layer extends onto the rear surfaceof the semiconductor substrate and is connected to the via conductivelayer.
 6. The image sensor of claim 4, wherein the at least two throughvia structures overlap the pad structure in the direction extendingperpendicular to the rear surface of the semiconductor substrate, andeach of the at least two through via structures includes a viaconductive layer on an internal wall of a through via trench, the viaconductive layer connected to the pad trench, the via conductive layerconnected to the pad conductive layer.
 7. The image sensor of claim 1,further comprising: a pixel isolation region between two adjacent onesof the plurality of photoelectric conversion regions, the pixelisolation region being on an internal wall of a pixel isolation trench,wherein the pixel isolation trench extends into the semiconductorsubstrate from the rear surface of the semiconductor substrate towardthe front surface of the semiconductor substrate, and the pixelisolation trench does not completely penetrate the semiconductorsubstrate.
 8. The image sensor of claim 7, wherein the isolationstructure has a sidewall inclined at a first angle with respect to therear surface of the semiconductor substrate, the pixel isolation regionhas a sidewall inclined at a second angle with respect to the rearsurface of the semiconductor substrate, and the second angle is the sameas the first angle.
 9. The image sensor of claim 1, further comprising:a pixel isolation region between two adjacent ones of the plurality ofphotoelectric conversion regions, the pixel isolation region being on aninternal wall of a pixel isolation trench, wherein the pixel isolationtrench penetrates the semiconductor substrate from the front surface ofthe semiconductor substrate toward the rear surface of the semiconductorsubstrate, and the pixel isolation region extends in the pixel isolationtrench from the front surface of the semiconductor substrate toward therear surface of the semiconductor substrate.
 10. The image sensor ofclaim 9, wherein the pixel isolation region comprises: a pixel isolationlayer on the internal wall of the pixel isolation trench; and a pixelisolation conductive layer on the pixel isolation layer, the pixelisolation conductive layer filling the pixel isolation trench.
 11. Animage sensor comprising: a semiconductor substrate including a pixelregion and a pad region; a plurality of photoelectric conversion regionsin the pixel region; a pixel isolation region between two adjacent onesof the plurality of photoelectric conversion regions, the pixelisolation region at least partially extending from a rear surface of thesemiconductor substrate; an interconnect structure on a front surface ofthe semiconductor substrate; a pad structure in the pad region, the padstructure on the rear surface of the semiconductor substrate; at leasttwo through via structures in the pad region, each of the at least twothrough via structures electrically connected to the interconnectstructure through the semiconductor substrate; and an isolationstructure at least partially extending into the semiconductor substrateand through the pad region of the semiconductor substrate from the rearsurface of the semiconductor substrate, in a direction extendingperpendicular to the rear surface of the semiconductor substrate, theisolation structure surrounding the pad structure and the at least twothrough via structures.
 12. The image sensor of claim 11, wherein theisolation structure is not between the pad structure and the at leasttwo through via structures within the semiconductor substrate, and theisolation structure is not between two adjacent through via structuresof the at least two through via structures within the semiconductorsubstrate.
 13. The image sensor of claim 11, wherein the pad structurecomprises: a pad insulation layer extending conformally on an internalwall of a pad trench extending into the semiconductor substrate from therear surface of the semiconductor substrate; and a pad conductive layeron the pad insulation layer, the pad conductive layer filling the padtrench.
 14. The image sensor of claim 13, wherein the at least twothrough via structures are spaced apart from the pad structure in adirection parallel with the rear surface of the semiconductor substrate,each of the at least two through via structures includes a viaconductive layer on an internal wall of a through via trench, thethrough via trench extending through the semiconductor substrate, thevia conductive layer isolated from direct contact with the pad trench,and a portion of the pad conductive layer extends onto the rear surfaceof the semiconductor substrate and is connected to the via conductivelayer.
 15. The image sensor of claim 14, further comprising: a backsideinsulation layer on the rear surface of the semiconductor substrate,wherein the portion of the pad conductive layer is on the backsideinsulation layer.
 16. The image sensor of claim 13, wherein the at leasttwo through via structures overlap the pad structure in the directionextending perpendicular to the rear surface of the semiconductorsubstrate, and each of the at least two through via structures includesa via conductive layer on an internal wall of a through via trench, thevia conductive layer connected to the pad trench, the via conductivelayer connected to the pad conductive layer.
 17. The image sensor ofclaim 11, wherein the pixel isolation region is on an internal wall of apixel isolation trench, the pixel isolation trench extends into thesemiconductor substrate from the rear surface of the semiconductorsubstrate toward the front surface of the semiconductor substrate, andthe pixel isolation trench does not completely penetrate thesemiconductor substrate.
 18. The image sensor of claim 17, wherein theisolation structure has a sidewall inclined at a first angle withrespect to the rear surface of the semiconductor substrate, the pixelisolation region has a sidewall inclined at a second angle with respectto the rear surface of the semiconductor substrate, and the second angleis the same as the first angle.
 19. The image sensor of claim 11,wherein the pixel isolation region is on an internal wall of a pixelisolation trench, and the pixel isolation trench penetrates thesemiconductor substrate from the front surface of the semiconductorsubstrate toward the rear surface of the semiconductor substrate. 20.The image sensor of claim 19, wherein the pixel isolation regioncomprises: a pixel isolation layer on the internal wall of the pixelisolation trench; and a pixel isolation conductive layer on the pixelisolation layer, the pixel isolation conductive layer filling the pixelisolation trench.